Thank you, Rick and others that responded to my post.
I chose a more flexible solution.
1/ Drop the cable modem in the office, attached to a router, wireless access point, and my desktop computers.
2/ Further, connect the router to a 5 GHz wireless bridge.
3/ Put another 5 GHz bridge in the family room and my son's room, where I can wire it to Apple TV, XBox, etc.
This eliminates all wires, which will likely be obsolete soon any way.
The equipment I have to buy is limited to the three bridges. This is likely cheaper than pulling wires and can be expanded cheaply.
I also chose, separately, a pair of wireless Klipsch speakers that install in can lights in the ceiling of the family room. Each can light has an LED with 50K hours of life, all controlled by a remote, which can dim the lights and the volume of the speakers. The speakers are not home theater quality (no surround, etc) but are portable, expandable and can be supplemented by hi-fi when the time comes -- right after the popcorn machine and the arena seats.
Martin